WOHO! I love this story. But is this a crossover? I know there is a BFG in Doom 3, and another one in Friday the 13th. But Harry also sounds like an Astartes warrior, or at least a Brotherhood member, from Warhammer. All my ten go to this.

Good, however, Hermione announcing her pregnancy three days after the first time they have sex is totally unrealistic. For the sake of making the story more convincing, it would be better to nix that night being their first time, imho. otherwise, good.